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1.
J Neurol ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801431

RESUMO

OBJECTIVE: The aim of our study was to analyze the characteristics of patients with autoimmune encephalitis (AE) to identify prognostic factors associated with the development of drug-resistant epilepsy (DRE). METHODS: In this retrospective observational cohort study, we enrolled adult patients with AE between January 2016 and December 2022. The patients were categorized into two groups based on the presence or absence of DRE at the last follow-up. The predictors of the development of DRE were investigated using logistic regression analysis. RESULTS: Among 121 AE patients, 75.2% (n = 91) experienced acute symptomatic seizures, and 29.8% (n = 36) developed DRE at the last follow-up. On multivariate regression analysis, the factors associated with DRE were antibody negativity (OR 3.628, 95% CI 1.092-12.050, p = 0.035), focal seizure (OR 6.431, 95% CI 1.838-22.508, p = 0.004), refractory status epilepticus (OR 8.802, 95% CI 2.445-31.689, p = 0.001), interictal epileptiform discharges on EEG (OR 6.773, 95% CI 2.206-20.790, p = 0.001), and T2/FLAIR hyperintensity in the limbic system (OR 3.286, 95% CI 1.060-10.183, p = 0.039). CONCLUSIONS: In this study, the risk of developing DRE was mainly observed among AE patients who were negative for antibodies or had focal seizures, refractory status epilepticus, interictal epileptiform discharges on EEG, and T2/FLAIR hyperintensity in the limbic system.

2.
ACS Appl Mater Interfaces ; 16(9): 11957-11972, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38393750

RESUMO

The usage of a conductive hydrogel in wearable sensors has been thoroughly researched recently. Nonetheless, hydrogel-based sensors cannot simultaneously have excellent mechanical property, high sensitivity, comfortable wearability, and rapid self-healing performance, which result in poor durability and reusability. Herein, a robust conductive hydrogel derived from one-pot polymerization and subsequent solvent replacement is developed as a wearable sensor. Owing to the reversible hydrogen bonds cross-linked between polymer chains and clay nanosheets, the resulting conductive hydrogel-based sensor exhibits outstanding flexibility, self-repairing, and fatigue resistance performances. The embedding of graphene oxide nanosheets offers an enhanced hydrogel network and easy release of wearable sensor from the target position through remote irradiation, while Li+ ions incorporated by solvent replacement endow the wearable sensor with low detection limit (sensing strain: 1%), high conductivity (4.3 S m-1) and sensitivity (gauge factor: 3.04), good freezing resistance, and water retention. Therefore, the fabricated wearable sensor is suitable to monitor small and large human motions on the site and remotely under subzero (-54 °C) or room temperature, indicating lots of promising applications in human-motion monitoring, information encryption and identification, and electronic skins.


Assuntos
Hidrogéis , Humanos , Argila , Condutividade Elétrica , Ligação de Hidrogênio , Movimento (Física) , Solventes
3.
Micromachines (Basel) ; 14(5)2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37241543

RESUMO

The structure used in this study is as follows: substrate/PMMA/ZnS/Ag/MoO3/NPB/Alq3/LiF/Al. Here, PMMA serves as the surface flattening layer, ZnS/Ag/MoO3 as the anode, NPB as the hole injection layer, Alq3 as the emitting layer, LiF as the electron injection layer, and aluminum as the cathode. The properties of the devices with different substrates were investigated using P4 and glass, developed in the laboratory, as well as commercially available PET. After film formation, P4 creates holes on the surface. The light field distribution of the device was calculated at wavelengths of 480 nm, 550 nm, and 620 nm using optical simulation. It was found that this microstructure contributes to light extraction. The maximum brightness, external quantum efficiency, and current efficiency of the device at a P4 thickness of 2.6 µm were 72,500 cd/m2, 1.69%, and 5.68 cd/A, respectively. However, the maximum brightness of the same structure with PET (130 µm) was 9500 cd/m2. The microstructure of the P4 substrate was found to contribute to the excellent device performance through analysis of the AFM surface morphology, film resistance, and optical simulation results. The holes formed by the P4 substrate were created solely by spin-coating the material and then placing it on a heating plate to dry, without any special processing. To confirm the reproducibility of the naturally formed holes, devices were fabricated again with three different emitting layer thicknesses. The maximum brightness, external quantum efficiency, and current efficiency of the device at an Alq3 thickness of 55 nm were 93,400 cd/m2, 1.7%, and 5.6 cd/A, respectively.

4.
Ann Transl Med ; 11(7): 288, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37090053

RESUMO

Autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A) is an antibody-related astrocytic disease for which a specific GFAP antibody serves as a biological marker. Indeed, cerebral spinal fluid positive and/or seropositivity for GFAP is an important basis for its diagnosis. However, because patients with autoimmune encephalitis or demyelinating diseases can have a similar antibody profile, termed overlapping autoimmune syndrome, it remains a challenge for clinicians to diagnose and suitably classify autoimmune GFAP-A. To further understand the significance of GFAP antibody detection in neuroimmune diseases, this article discusses GFAP antibodies in autoimmune GFAP-A, progress for detection of GFAP antibodies, diagnostic significance of GFAP antibodies in prototypical disease, as well as overlapping syndrome.

5.
Membranes (Basel) ; 12(12)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36557145

RESUMO

We use polyethylene glycol as an additive to explore how the hydrogen bonding of this additive changes the properties of SA8 blended sulfonated polyetheretherketone (SPEEK) composite films. We mixed a 5%wt polyethylene glycol solution into a 12.5%wt SA8 solution, and then prepared a film with a total weight of 40 g at a ratio of 1:99. The SA8 (PEG) solution was prepared and then mixed with 5%wt SPEEK solution, and a film-forming solution with a total weight of 8g in different mixing ratios was created. Polyethylene glycol (PEG) was mixed into the sulfonated polyarylether polymer SA8 to form physical cross-linking. Therefore, the sulfonated polyether ether ketone SPEEK was mixed in, and it exhibited good thermal stability and dimensional stability. However, there was some decrease in proton conductivity as the proportion of SPEEK increased. Although SPEEK mixed with sulfonated polymer reduces the proton conductivity, the physical cross-linking of PEG can improve the proton conductivity of the composite membrane, and adding SPEEK can not only solve the problem of the high sulfonation film swelling phenomenon, it can also improve the dimensional stability of the film through the hydrogen bonding force of PEG and obtain a composite film with excellent properties.

6.
Membranes (Basel) ; 12(10)2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36295733

RESUMO

This study fabricated a composite ePTFE-backed proton-exchange membrane by filling the pores on the ePTFE backing with sulfonated polyarylene ethers through an externally supplied electric field. The morphology changes were observed under an SEM. The results suggested that the application of an electric field had led to the effective filling of pores by polymers. In addition, the composite membrane featured good dimensional stability and swelling ratio, and its water uptake, proton conductivity and component efficiency increased with voltage. It is found in this study that the external application of an electric field resulted in the effective filling of pores in the ePTFE by sulfonated polyarylene ether polymers and, thus, an improved composite membrane performance.

7.
Membranes (Basel) ; 12(6)2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35736289

RESUMO

In this study, a series of high molecular weight ionomers of hexaarylbenzene- and fluorene-based poly(arylene ether)s were synthesized conveniently through condensation and post-sulfonation modification. The use a of blending method might increase the stacking density of chains and affect the formation both of interchain and intrachain proton transfer clusters. Multiscale phase separation caused by the dissolution and compatibility differences of blend ionomer in high-boiling-point solvents was examined through analysis and simulations. The blend membranes produced in this study exhibited a high proton conductivity of 206.4 mS cm−1 at 80 °C (increased from 182.6 mS cm−1 for precursor membranes), excellent thermal resistance (decomposition temperature > 200 °C), and suitable mechanical properties with a tensile strength of 73.8−77.4 MPa. As a proton exchange membrane for fuel cell applications, it exhibits an excellent power efficiency of approximately 1.3 W cm−2. Thus, the ionomer membranes have strong potential for use in proton exchange membrane fuel cells and other electrochemical applications.

8.
Polymers (Basel) ; 13(21)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34771406

RESUMO

Aromatic polyimine (PIM) was prepared through condensation polymerization between p-phenylene diamine and terephthalaldehyde via Schiff reactions. PIM can be physically crosslinked with ferrous ions into gel. The gel-composites, calcined at two consecutive stages, with temperatures ranging from 600 to 1000 °C, became Fe- and N-doped carbonaceous organic frameworks (FeNC), which demonstrated both graphene- and carbon nanotube-like morphologies and behaved as an electron-conducting medium. After the two-stage calcination, one at 1000 °C in N2 and the other at 900 °C in a mixture of N2 and NH3, an FeNC composite (FeNC-1000A900) was obtained, which demonstrated a significant O2 reduction peak in its current-voltage curve in the O2 atmosphere, and thus, qualified as a catalyst for the oxygen reduction reaction. It also produced a higher reduction current than that of commercial Pt/C in a linear scanning voltage test, and the calculated e-transferred number reached 3.85. The max. power density reached 400 mW·cm-2 for the single cell using FeNC-1000A900 as the cathode catalyst, which was superior to other FeNC catalysts that were calcined at lower temperatures. The FeNC demonstrated only 10% loss of the reduction current at 1600 rpm after 1000 redox cycles, as compared to be 25% loss for the commercial Pt/C catalyst in the durability test.

9.
Membranes (Basel) ; 11(8)2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34436389

RESUMO

Series of partially fluorinated sulfonated poly(arylene ether)s were synthesized through nucleophilic substitution polycondensation from three types of diols and superhydrophobic tetra-trifluoromethyl-substituted difluoro monomers with postsulfonation to obtain densely sulfonated ionomers. The membranes had similar ion exchange capacities of 2.92 ± 0.20 mmol g-1 and favorable mechanical properties (Young's moduli of 1.60-1.83 GPa). The membranes exhibited considerable dimensional stability (43.1-122.3% change in area and 42.1-61.5% change in thickness at 80 °C) and oxidative stability (~55.5%). The proton conductivity of the membranes, higher (174.3-301.8 mS cm-1) than that of Nafion 211 (123.8 mS cm-1), was the percent conducting volume corresponding to the water uptake. The membranes were observed to comprise isolated to tailed ionic clusters of size 15-45 nm and 3-8 nm, respectively, in transmission electron microscopy images. A fuel cell containing one such material exhibited high single-cell performance-a maximum power density of 1.32 W cm2 and current density of >1600 mA cm-2 at 0.6 V. The results indicate that the material is a candidate for proton exchange membranes in fuel cell applications.

10.
Polymers (Basel) ; 13(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34301136

RESUMO

Oleic acid (OA)-modified Fe3O4 nanoparticles were successfully covered with polyanilines (PANIs) via inverse suspension polymerization in accordance with SEM and TEM micrographs. The obtained nanoparticles were able to develop into a ferrite (α-Fe) and α″-Fe16N2 mixture with a superparamagnetic property and high saturated magnetization (SM) of 245 emu g-1 at 950 °C calcination under the protection of carbonization materials (calcined PANI) and other iron-compounds (α″-Fe16N2). The SM of the calcined iron-composites slightly decreases to 232 emu g-1 after staying in the open air for 3 months. The calcined mixture composite can be ground into homogeneous powders without the segregation of the iron and carbon phases in the mortar without significantly losing magnetic activities.

11.
Polymers (Basel) ; 12(12)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371521

RESUMO

Triethylenetetramine (TETA) and thiourea complexed Cobalt(II) (Co(II)) ions are used as cathode catalysts for proton exchanged membrane fuel cells (PEMFCs) under the protection of polyaniline (PANI) which can become a conducting medium after calcination. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra clearly reveal the presence of typical carbon nitride and sulfide bonds of the calcined Nitrogen (N)- or Sulfur (S)-doped co-catalysts. Clear (002) and (100) planes of carbon-related X-ray diffraction patterns are found for co-catalysts after calcination, related to the formation of a conducting medium after the calcination of PANI. An increasing intensity ratio of the D to G band of the Raman spectra reveal the doping of N and S elements. More porous surfaces of co-catalysts are found in scanning electronic microscopy (SEM) micropictures when prepared in the presence of both TETA and thiourea (CoNxSyC). Linear sweep voltammetry (LSV) curves show the highest reducing current to be 4 mAcm-2 at 1600 rpm for CoNxSyC, indicating the necessity for both N- and S-doping. The membrane electrode assemblies (MEA) prepared with the cathode made of CoNxSyC produces the highest maximum power density, close to 180 mW cm-2.

12.
Sci Total Environ ; 745: 141004, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32738688

RESUMO

Lead (Pb) exposure may cause severe health outcomes such as decreased fertility, joint pain and neurological disorders. It is important to know the Pb exposure level in tea and the risk assessment for local residents who drink brick tea daily. This study detected sixteen brick tea samples over 26 years and fifteen green tea samples in 2011 in a southeast city of Hubei province. The Pb content in brick tea was found to increase rapidly with the fast development of industrial activities represented by car sales from 1985 to 2011, which was less susceptible to gasoline. The concentrations of Pb in 16 brick tea were in the range of 1.77-17.8 mg/kg with a mean value of 11.1 mg/kg. Their percentiles P50, P90, and P95 were 13.22, 16.95, and 17.21 mg/kg. A regressional model was built, suggesting strong correlation between the Pb content in brick tea and the car sales. The concentrations of Pb in 15 green tea samples were between 0.36-1.30 mg/kg with a mean value of 0.66 mg/kg and the percentiles P50, P90, and P95 were 0.62, 1.05, and 1.23 mg/kg. The MOE values of brick tea and green tea were all greater than 1 just considering tea consumption which displayed low Pb exposure risk. By adding the Pb exposure by food, the MOE values for green tea were still greater than 1 while the MOE values of brick tea were less than 1 suggesting a potential risk of Pb exposure to the people drinking brick tea daily, who should pay more attention.


Assuntos
Chumbo , Chá , China , Medição de Risco
13.
Materials (Basel) ; 13(7)2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32224884

RESUMO

The small sized copper nanoparticles (Cu-NPs), prepared in the presence of triethylene tetramine (TETA) and assisted with microwave irradiation, have an extremely low melting temperature. Melting of the small sizezd Cu-NPs can be triggered by the heat generated from the e-beam irradiation during SEM and TEM image construction. The dispersed Cu atoms around the agglomerated big Cu particles can undergo recrystallization immediately due to the strong driving force of the huge temperature difference to normal melting temperature (Tm = 1085 °C). Some of the Cu-NPs with bigger sizes also recrystallize and agglomerate into dense, big particles. According to X-ray diffraction patterns, these particles can agglomerate into compact, ordered Cu crystals in less than five minutes at 60 °C. The melting and recrystallization related endothermic and exothermic phase transitions of Cu-NPs can be found from differential scanning calorimeter (DSC) thermograms and optical microscopic pictures.

14.
Polymers (Basel) ; 12(3)2020 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-32182689

RESUMO

Calcination reduction reaction is used to prepare Pt/EB (emeraldine base)-XC72 (Vulcan carbon black) composites as the cathode material of a proton exchange membrane fuel cell (PEMFC). The EB-XC72 core-shell composite obtained from directly polymerizing aniline on XC72 particles is able to chelate and capture the Pt-ions before calcination. X-ray diffraction spectra demonstrate Pt particles are successfully obtained on the EB-XC72 when the calcined temperature is higher than 600 °C. Micrographs of TEM and SEM illustrate the affluent, Pt nanoparticles are uniformly distributed on EB-XC72 at 800 °C (Pt/EB-XC72/800). More Pt is deposited on Pt/EB-XC72 composite as temperatures are higher than 600 °C. The Pt/EB-XC72/800 catalyst demonstrates typical type of a cyclic voltammograms (C-V) curve of a Pt-catalyst with clear Pt-H oxidation and Pt-O reduction peaks. The highest number of transferred electrons during ORR approaches 3.88 for Pt/EB-XC72/800. The maximum power density of the single cell based on Pt/EB-XC72/800 reaches 550 mW cm-2.

15.
Int J Neurosci ; 130(2): 186-192, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31696761

RESUMO

Background and Purpose: Oxidative stress is involved in the development of infections. However, whether oxidative stress indicators can be used as markers of stroke-associated infection (SAI) is still unclear. The purpose of this study was to test the predictive values of superoxide dismutase (SOD) and malondialdehyde (MDA) levels for SAI incidence.Methods: A total of 45 consecutive patients with ischemic stroke who were admitted to our hospital were enrolled. A prospective study was carried out to observe the occurrence of SAI during the first 7 days after stroke. Accordingly, the patients were divided into SAI and non-SAI groups. The relationship between SOD and MDA serum levels and SAI was analyzed.Results: The patients in the SAI group had significantly higher serum SOD levels than those in the non-SAI group (41.638 ± 3.428 U/ml vs. 36.542 ± 9.114 U/ml, p = 0.033). However, there were no significant differences in MDA levels between the SAI and non-SAI group (p > 0.05). The discriminating ability of serum SOD level for SAI was measured using an ROC curve. Serum level of SOD >38.16 U/ml was useful in diagnosing SAI with a sensitivity of 88% and a specificity of 61%. Kaplan-Meier curves showed that the group with serum SOD level >38.16 U/ml had higher rates of SAI incidence (χ2 = 9.688, p = 0.002; log rank test). Furthermore, Cox regression analysis indicated that a serum SOD level >38.16 U/ml was an independent risk factor for SAI (hazard ratio = 5.836; 95% CI, 1.298-26.244; p = 0.021).Conclusions: Acute-phase serum SOD level could be a predictor of SAI.


Assuntos
Isquemia Encefálica/sangue , Infecções/sangue , Infecções/diagnóstico , Inflamação/sangue , Estresse Oxidativo , Acidente Vascular Cerebral/sangue , Superóxido Dismutase/sangue , Idoso , Biomarcadores/sangue , Isquemia Encefálica/complicações , Feminino , Humanos , Infecções/etiologia , Inflamação/etiologia , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Estresse Oxidativo/fisiologia , Estudos Prospectivos , Sensibilidade e Especificidade , Acidente Vascular Cerebral/complicações
16.
Biol Trace Elem Res ; 196(2): 494-501, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31656014

RESUMO

The purpose of this research is to investigate the absorption, distribution, excretion, and pharmacokinetics of selenite in rats after intragastric administration, and thus illustrate the efficiency of selenium (Se) supplementation. After a single gavage of sodium selenite, a concentration of Se in plasma and tissues was determined by inductively coupled plasma mass spectrometry (ICP-MS) at different time points. Through fitting the data with the metabolic kinetic model, the corresponding kinetic parameters were determined for plasma and tissues, including kidney, liver, heart, muscle, and gonad. While the metabolic kinetics of sodium selenite in plasma, liver, and kidney of rats was well reflected by a two-compartment open model, that in heart and gonad was fitted to a one-compartment open model, and that in muscle was fitted to a one-compartment open model with a lag time. The results indicate that sodium selenite was absorbed by plasma and tissues quickly and was eliminated slowly after intragastric administration. Based on the results, we propose that multi-supplementation of Se with low dosage is superior to single supplementation with high dosage, in terms of avoiding selenosis.


Assuntos
Gônadas/metabolismo , Coração , Rim/metabolismo , Fígado/metabolismo , Músculos/metabolismo , Selenito de Sódio/farmacocinética , Administração Oral , Animais , Feminino , Gônadas/química , Rim/química , Cinética , Fígado/química , Masculino , Músculos/química , Ratos , Ratos Wistar , Selenito de Sódio/administração & dosagem , Selenito de Sódio/sangue , Distribuição Tecidual
17.
Neuroimmunomodulation ; 26(5): 234-238, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31661704

RESUMO

OBJECTIVE: To explore the diversity and clinical features of anti-glutamate decarboxylase (GAD) antibody-associated neurological diseases. METHODS: Clinical data of a series of 5 patients positive for anti-GAD antibodies were retrospectively analyzed. RESULTS: All 5 patients were female, with a median age of 41.5 years (range 19-60 years). Their neurological symptoms included stiff-person syndrome (SPS), encephalitis, myelitis, cramp, visual loss, and paresthesia. Three patients (60%) were diagnosed with tumors, 2 cases of thymic tumor and 1 of breast cancer. On immunohistochemistry for tumor pathology, expression of GAD65 was found only in 1 patient. Four patients (80%) had abnormal brain MRI findings. All patients received immunotherapy and improved significantly after treatment, but 4 (80%) then experienced a relapse. CONCLUSIONS: Neurological manifestations in anti-GAD-positive patients are diverse and include SPS, encephalitis, myelitis, cramp, visual loss, and paresthesia.


Assuntos
Autoanticorpos/imunologia , Doenças Autoimunes do Sistema Nervoso/fisiopatologia , Glutamato Descarboxilase/imunologia , Síndromes Paraneoplásicas do Sistema Nervoso/fisiopatologia , Adulto , Doenças Autoimunes do Sistema Nervoso/diagnóstico por imagem , Doenças Autoimunes do Sistema Nervoso/imunologia , Encéfalo/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Encefalite/diagnóstico por imagem , Encefalite/imunologia , Encefalite/fisiopatologia , Feminino , Glutamato Descarboxilase/metabolismo , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Cãibra Muscular/imunologia , Cãibra Muscular/fisiopatologia , Mielite/imunologia , Mielite/fisiopatologia , Síndromes Paraneoplásicas do Sistema Nervoso/diagnóstico por imagem , Síndromes Paraneoplásicas do Sistema Nervoso/imunologia , Parestesia/imunologia , Parestesia/fisiopatologia , Recidiva , Estudos Retrospectivos , Rigidez Muscular Espasmódica/imunologia , Rigidez Muscular Espasmódica/fisiopatologia , Neoplasias do Timo/metabolismo , Transtornos da Visão/imunologia , Transtornos da Visão/fisiopatologia , Adulto Jovem
18.
Polymers (Basel) ; 11(8)2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31430934

RESUMO

Calcinated tris(ethylenediamine)iron(III) chloride was used as a non-precious metal catalyst (NPMCs) for a proton exchanged membrane fuel cell (PEMFC) under the protection of polyaniline (PANI), which behaves as both nitrogen source and carbon supporter. The optimal ratio of FeCl3/EDA was found to be close to 1/3 under the consideration of the electrocatalytic performance, such as better oxygen reduction reaction (ORR) and higher power density. Two-stage calcination, one at 900 °C in N2 and the other at 800 °C in mixed gases of N2 and NH3, result in an FeNxC catalyst (FeNC-900-800-A) with pretty high specific surface area of 1098 m2·g-1 covered with both micro- and mesopores. The ORR active sites focused mainly on Fe-Nx bonding made of various pyridinic, pyrrolic, and graphitic N-s after calcination. The max. power density reaches 140 mW·cm-2 for FeNC-900-800-A, which is superior to other FeNxC catalysts, experiencing only one-stage calcination in N2. The FeNxC demonstrates only 10 mV half-wave-voltage (HWV) loss at 1600 rpm after 1000 redox cycles, as compared to be 27 mV for commercial Pt/C catalyst in the durability test.

19.
Polymers (Basel) ; 10(12)2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30961313

RESUMO

The Pt elements are prepared via the redox reaction with microwave (MW) irradiation in the presence of poly(p-phenylenediamine) (PpPD) which is polymerized on XC72 carbon matrix (PpPD/XC72), behaving as reducing agent. The free primary amines of PpPD are actually converted (oxidized) to secondary ones (5,10-dihydrophenazine) after MW irradiation. Transmission electronic microscopy (TEM) micrographs reveal the prepared Pt nanoparticles are well-dispersed on the carbon matrix like commercial Pt-implanted carbon nanocomposite (Pt/C). From the residue weights of thermogravimetric analysis (TGA) thermograms of Pt-loaded PpPD/XC72 (PpPD/XC72-Pt-MW), more Pt (18.49 wt %) nanoparticles are implanted on PpPD/XC72 composite. The Pt-implanted wt % on PpPD/XC72 matrix is just slightly lower than that of commercial Pt/C (22.30 wt %). The Pt-catalyst supports of PpPD/XC72-Pt-MW illustrate typical cyclic voltammograms (C-V) of Pt-catalyst, including significant Pt⁻H oxidation and Pt⁻O reduction peaks. The electrochemical active surface area of PpPD/XC72-Pt-MW is found to be as high as 60.1 m² g-1. Max. number of electron transfer during oxygen reduction reaction (ORR) approaches 3.83 for PpPD/XC72-Pt-MW, higher than that of commercial Pt/C (3.62). Single cell based on PpPD/XC72-Pt-MW demonstrates much higher specific max. power density to be 34.6 mW cm-2 Pt, higher than that single cell prepared with commercial Pt/C electrode (30.6 mW cm-2 Pt).

20.
Gene ; 642: 522-532, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29197588

RESUMO

Efforts have been made to characterize the high-altitude adaption in Tibetan pigs and identified vast of genes or genomic regions undergone natural selection. Nonetheless, information concerning gene expression and DNA methylation changes response to low-altitude acclimation in Tibetan pigs is long overdue. To explore the exceptional mechanisms of gene expression and DNA methylation that are induced by low altitude environments in Tibetan pigs, we performed a comparative transcriptomic and DNA methylation analysis of skeletal muscle between indigenous Tibetan pigs that reside in high altitude regions (~4000m) and their counterparts that migrated to the geographically neighboring low-altitude regions (~500m) for nearly ten generations. Many genes that related to hypoxia response (EGLN3 and FLT1) and energy metabolism (TFB2M) were differentially expressed, but without significant DNA methylation changes. We also found genes embedded in differentially methylated regions were mainly involved in 'Starch and sucrose metabolism', 'glucuronosyltransferase activity' processes. Specifically, our results showed increased SIN3A mRNA expression, with hypomethylation status of its promoter, in longissimus dorsi muscle of low-altitude Tibetan pig. Another gene, CACNG6, showed decreasing expression level with an elevated methylation in its intron 3. These results indicated DNA-methylation-mediated expression alterations in low-altitude acclimation. We envision that this study will serve as a valuable resource for mammal acclimation research and agricultural food industry.


Assuntos
Aclimatação , Metilação de DNA , Perfilação da Expressão Gênica/métodos , Sus scrofa/genética , Altitude , Animais , Ilhas de CpG , Músculo Esquelético/metabolismo , Filogenia , Regiões Promotoras Genéticas , Seleção Genética , Suínos
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